Metal complexes of dithiobiurets

ABSTRACT

METAL COMPLEXES OF DITHIOBIUTETS HAVE BEEN FOUND TO EXHIBIT FUNGICIDAL AND GROWTH REGULATING ACTIVITY. EXEMPLARY OF SUCH CONPOUNDS ARE THOSE REPRESENTED BY THE FOLLOWING STRUCTURE:   R1-N(-R2)-C(=Y)-N(-N(-R5)-R6)-C(=Y)-N(-R3)-R4 . M(X)N   WHEREIN R1-R2 ARE EACH SELECTED FROM A GROUP CONSISTING OF HYDROGEN C1-C10 ALKYL C1-C10 ALKENYL C3-C10 CYCLOALKYL OPTIONALLY SUBSTITUTED WITH C1-C8 ALKYL CHLORO, BROMO, C6-C10 ARYL, OPTIONALLY SUBSTITUTED WITH C1-C10 ALKARYL. CHLORO BROMO C1-C10 ARYL ALKYL C1-C10 ALKARYL. R1- AND R2 AND/OR R3 AND R4 AND/OR R5 OR R6 TOGETHER CAN BE A CARBOCYCLIC RING CONTAINING ONE OR MORE HETEROATOMS SUCH AS N OR S; M IS ONE SELECTED FROM THE GROUP CONSISTING OF ZINC IRON NICKEL COPPER MANGANESE AND COBALT; X IS AN ANION BEING ONE SELECTED FROM THE GROUP CONSISTING OF CHLORIDE BROMIDE, IODIDE SULFATE NITRATE PHOSPHATE AND ACETATE; N IS AN INTEGER DETERMINED BY THE VALENCE OF THE METAL ATOMS, AND Y IS EITHER O OR S.

United States Patent US. Cl. 260-429 R 2 Claims ABSTRACT OF THE DISCLOSURE Metal complexes of dithiobiurets have been found to exhibit effective fungicidal and growth regulating activity. Exemplary of such compounds are those represented by the following structure:

wherein R R are each selected from a group consisting of hydrogen, C -C alkyl, C -C alkenyl, C -C cycloalkyl optionally substituted with C -C alkyl chloro, bromo, C -C aryl, optionally substituted with C -C alkyl, chloro, bromo, Cr C aryl alkyl, C -C alkaryl.

R and R and/or R and R and/or R and R together can be a carbocyclic ring containing one or more heteroatoms such as N or S; M is one selected from the group consisting of zinc, iron, nickel, copper, manganese and cobalt; X is an anion being one selected from the group consisting of chloride, bromide, iodide, sulfate, nitrate, phosphate and acetate; n is an integer determined by the valence of the metal atoms, and Y is either 0 or S. i 1

This is a division of application Ser. No. 32,337, filed on Apr. 27, 1970, now Pat. No. 3,686,244.

' This invention relates to the use of metal complexes of dithiobiurets as growth regulants and fungicides.

' In one aspect this invention relates to the use of the aforesaid compounds as fruit-thinning agents. In another aspect, this invention relates to the use of the aforesaid compounds as plant growth regulants. In yet another aspect, this invention relates to the use of the aforesaid compounds as crop harvest aids. In another aspect, this invention relates to the use of the aforesaid compounds as fungicides.

The board class of growth regulants are those compounds having an ability to regulate vegetative, flowering and fruiting characteristics of crops produced throughout the world. With growth regulators, it is now possible to chemically control and alter the physiological processes in the growing crops, which up until the advent of such technology could only be triggered by natural and climatic conditions. Thus, it is possible to produce crops of higher quality and with greater flexibility in harvesting procedures. Various theories have been proposed for explaining the mechanisms of chemical growth regulants such as, they prevent fertilization of freshly-opened flowers by inducing an incompatible condition between the stylar tissue and the pollen tubes. Another theory is that a crop is thinned because of an increased drop in young fruitlets due to accelerated ethylene generation by the particular treatment. Developing fruitlets on weak spurs with a limited food supply may be more susceptible 3,799,960 Patented Mar. 26, 1974 than those with an abundant supply so that the elimination of clusters where two or more fruits have set on the same spur can be explained on the basis of competition for food; that is, the fruitlets having the greatest advantage for food supply possess the most resistance to the chemical treatment.

Whatever may be the actual mechanism involved in chemical fruit thinning or in the removal of-unwanted growth for particular plants, or in the abscission of the fruit when the plant matures, thereby regulating the harvest season, the growth regulants have indeed opened up an entirely new field for agricultural chemicals.

An object of the present invention is to provide a process for thinning fruit plants, such as citrus, stone and pome fruits, small fruits and nuts, in which a chemical material may be employed within a relatively narrow range of concentrations without danger of either overthinning, or causing foliage and fruit damage. Another object of the invention is to provide a process of thinning fruits with a chemical agent which can effectively be applied to the trees over a relatively long period of time beginning with full bloom.

Yet another object of the invention is to provide a process for adjusting the rate and timing of abscission of undesirable late flowers and fruitlets prior to mechanical harvesting of mature crops.

A still further object of the invention is to provide a process for controlling the rate of final development and maturation of crops so as to regulate the timed abscission of the mature fruit, vegetables, nuts or berries.

A still further object of the invention is to provide a process for delaying the onset of normal maturation processes, such as, senescene or defoliation, thereby providing continued vegetative growth, as well as more intensely colored foliage.

A still further object of the invention is to prevent the photodegradation of dithiobiurets without in any way imparing its growth regulating or fungicidal activity.

Other objects and many of the attended advantages of this invention will be readily appreciated as the same becomes better understood by reference to the following detailed description.

Briefly, this invention relates to a method for regulating the growth of plants, said method comprising the step of treating growing plants with a material of the group consisting of those compounds represented by one of the following formulae:

wherein R -R are each selected from a group consisting of hydrogen, C -C alkyl, 0 -0 alkenyl, 0 -0 cycloalkyl optionally substituted with C -C alkyl chloro, brom0, C -C aryl, optionally substituted with C -C alkyl, chloro, bromo, C C arylalkyl, CI -C alkaryl.

R and R and/or R and R and/or R and R to gether can be a carbocyclic ring containing one or more heteroatoms such as N or S; M is one selected from the group consisting of zinc, iron, nickel, copper, manganese and cobalt; X is an anion being one selected from the group consisting of chloride, bromide, iodide, sulfate, nitrate, phosphate and acetate; n is an integer determined by the valence of the metal atoms, and Y is either 0 or S.

. Specific examples of compounds having the above structure are listed hereinbelow:

Compound number .1 Ferric chloride adduct of 1,1,5,5-tetramethyl-3 dimethylaminodithiobiuret.

2 Zinc chloride adduct of 1,1,5,5-tetramethyl-3 pentamethyleneaminodithiobiuret.

3 Ferric iodide adduct of 1,1,5,5-tetrarnet;hyl-3-drethylaminodithiobiuret.

4 Ferric sulfate adduct of 1,1,5,5-tetramethyl-3-diethylaminodithiobiuret.

Ferric nitrate adduct of 1,l-dimethyI-S-dimethylamino- 5,5-diethyldithiobiuret. Ferric chloride adducts of 1,1,5,5-tetraethyl-3-pentamethyleneaminodithiobiuret. 7 Cupric chloride adduct of 1,1,5,5-tetraethyl-3-hexamethyleneaminodithiobiuret. 8 Nickel chloride adduct; 01 1,1,5,5-tetramethyl-3-hexamethyleneaminodithiobiuret. 9 Cobaltous chloride adduct oi l,l,5,5-tetranrethyl-3- carbethoxyaminodithiobiuret. 10...-. Manganous chloride adduct oi 1,1,5,5-tetramethyl-3- di-npropylaminodithiobiuret. 11 Ferric bromide adduct of 1,1,5,5-tetraethyl-3-diethy1 aminodithiobiuret. 1'2 Ferric chloride adduct of 1,l-dimethyl-3-dimethylamrno- 5,5-di-n-propy1-dithiobiuret. 13 Ferric chloride adduct of 1,1,5,5-tetr'arncthyl-B-(N-methll V dodecylamino) dithiobiuret. 14 Ferric chloride adduct oi1,1-dimethyl-B-dimethylammo- 5,5-di-n-hexyldithiobiuret. '15.. Ferric chloride adduct of l,l-dimethyl-B-dimethylamrno- 5,5-pentamethylencdithiobiuret. 1e Fem'c chloride adduct of1,1,5,5-tetrarnethyl'll-(N-rnethy aniline) dithiobiuret. 17 Ferric chloride adduet of 1,1,5-trimethyl-3-dimcthylamino--n-dodecyldithiobiuret. 18 Ferric chloride adduct of 1 l-dimethyI-Ii-dimethylamrno- 5,5-(3-oxotetramethylene dithiobiuret. 19 Ferric chloride adduct of 1,1,5,5-di (3-oxotetramcthylene)- dimethylarninodithiobiuret. 20 Ferric chloride adduct oi 1,1-pentamethylene-3-drmethylamino-5,5(3-oxotctramethylene) dithiobiuret. 21 Ferric chloride adduct of 1,1 ,5,5-di(pentarnethylene)- 3-din1ethy1amirrodithiobiuret. 22 Ferric chloride adduct of 1,1,5-trimcthyl-3-drmethylamino-5-phenyldithiobiuret. 23 Ferric chloride adduct oi 1-methyl-1-phenyl-3-drmethy amino-5-ethyl-5-cyclohexyl-dithiobiuret. 24 Ferric chloride adduct of 1,1-dimethylJi-dimethylammo- 5-ethylb-phenyldithiobiuret. 25 Ferric chloride adduct of1,1-dimethyl-3-dimethylarmn0- 5-methyl-5-( i-chlorophcnyl) dithiobiuret. 26..-. Ferric chloride adduct oi 1,l-dirnethyl-3-dimethylarnrno- 5-methyl-5-(4-methylphenyl) dithiobiuret. 27 Ferric chloride adduct of 1,l-dimetlryl-3-dimethylamino- 5-methyl-5 t-methylthiophenyl)dithiobiuret. 28 Ferric chloride adduct of l,5dimethyl-1,5-diphenyl- 3-dimethylamlnodithiobiuret. 29 Ferric chloride adduct of1,1,5-trirnethyl-3dimethylamino-S-benzyldithiobiuret. 30 Ferric chloride adduct of 1,1,5-trimethyl3-hexamethylen amino-5-phenyldithiobiuret. 31 Ferric chloride adduct of 1,1 5-trirnethyl-3-pentamcthylene-amino-fi-pheny dithiobluret. 32--.. Ferric chloride adduct of1,1,5,5-tetramethyl-3[N-methy (G-chloropyridyl)amino1dithiobiuret.

.. Ferric chloride adduct of1,1-dimethy1-3-dimethylamrno- 5-n-propyl-5-phenyldithiobiuret.

.-. Ferric chloride adduct of 1,1-[ (N -methyl) -3-aminotetramethylene]-3-dimethylaminoe-methyl-5-phenY dithiobiuret.

- Ferric chloride adduct of 1,5-dimethyl-L5-dip1- Y 3-N-1nethylanilino dithiobiuret.

Ferric chloride adduct of 1 l-dimethyl-B-dlmethylamlno- 5,5-di(cyanomethyl) dit iobiuret.

Ferric chloride adduct of 1,1-dimethyl-8-dimethylamln0- 38-..-.--.-- Ferric chloride adduct oi 1,1dimethyl-3-dimethylamrno- 5-methyl-5-iurfuryldithiobiuret.

39.--.-.-..-. Fem'c chloride adduct of1,1-dimethyl-3-dimethylamino- 5-phenyl-fi-benzyldithiobiuret.

40 Ferric chloride adduct oi 1,1,5-trimethyl-3-dimethylamino-5-(2-picolyl)dithiobiuret.

41 Ferric chloride adduct of l,l,5-trimethyl-3;dimethylamino-54*.etrahydrofuriuryldithiobiuret. 42...-..'.. Ferric chloride adduct of 1 l-dimethyl-B-dimethylamino- 5-phenyl-5-N-acetamidodithiobiuret.

I The dithiobiurets which are the starting materials for forming the metal complexes of the subject invention are described in a copending case, Ser. No. 821,975 which was filed on May 5, 1969 in the name of James Zielinski and entitled Semicarbazide and Biuret Derivatives and Their Uses as Agricultural Pesticides and Animal Health Agents.

The metal complexes can be prepared accordingito the following reaction:

wherein R R MXn are defined as'hereinabove. This reaction can be carried out under a temperature ranging from --10 C. to 250 C., preferably 10 C. to 30 C. in the presence of solvents such as acetone; Jdimethyl formamide, tetrahydrofuran, ethanol, methanol, propanol and Water. Preferred solvent is acetoner lhe mole ratio of the dithiobiuret to the halide ranges from" 1:3 to 3:1 and preferably in the range of equal molar ratios of 1:1. The reaction can be run under atmospheric'pressurc. The concentration of the reactants in the solvent of no consequence. i The compounds may be appliedto the plants in a number of ways any time throughout the growing season depending on the type of effect desired. When used the metal complexes of the dithiobiurets are preferably formulated with a suitable inert carrier or diluent thereof. The term carrier or diluent as used herein means a material, which can be inorganic or organic; and synthetic or of natural origin, with which the active metal complexes of the dithiobiurets are mixed or formulated to facilitate its storage, transport, and handling and application of the plants or fungi to be treated.- The carrier is preferably biologically and chemically inert, and as used, can be a solid or fluid. When solid carriers are used, they are preferably particulate; however, other shapes and sizes of solid carrier can be employed as 'well. Such preferably solid carriers can be natural occurring minerals, although subsequently subjected to grinding, sieving, purification, and/or other treatments, including for example, gypsum; tripolite diatomaceous earth; min;- eral silicates such as mica, vermiculite, talc and pyrophyllite, clays of the montmorillonite, kaolinite, or attapulgite groups; calcium or magnesium limes, or calcite and dolomite; etc. Carriers produced synthetically, as for ex.- ample, synthetic hydrated silica oxides and; synthetic calcium silicates can also be used, and many proprietary products of this type are available commercially. The carrier can also be an elemental substance suchas sulfur or carbon, preferably an activated carbon. Fluid carriers can be liquids, as for example, Water, or an organic fluid, including a liquefied normally-vaporous or gaseous material, or a vaporous or gaseous material, and can be solvents or nonsolvents for the-active material. For example, the horticultural petroleum spray oils boiling in the range of from about 275 F. to about 575 F., or boiling in the range of about 575 F; to about 1,000 F. and having an unsulfonatable'residue of-"at least about 75% and preferably of at least about-%, or mixtures of these two types of oil, are particularly suitable liquid carriers. r The carrier can 'be mixed orformulated with' the active material during its manufacture or at any'stagc subsequently. The carrier can be mixed or formulated with the active material in any proportion depending on the nature of the carrier. One or more carriers, 'ri1dreover, can be used in combination. v

The compositions of this invention can be con-hem trates, suitable for storage or transport'andcontaining, for example, from about 5 to about 90% by weight of'the active dithiobiuret metal complexes, preferably hem about 20 to about 80 wt. percent. These concentrates can be diluted with the same or different carrier to a lower and higher concentrations can be applied if necessary.

The compositions of this invention can also be formulated as dusts. These comprise an intimate admixture of the active dithiobiuret metal complex and a finely powdered solid carrier such as aforedescribed. The powdered carriers can be oil-treated to improve adhesion to the surface to which they are applied. These dusts can be concentrates, in which case a highly sorptive carrier is preferably used. These require dilution with the same or a different finely powdered carrier, which can be of lower sorptive capacity, to a concentration suitable for application.

The compositions of the invention can be formulated as wettable powders comprising a major proportion of the dithiobiuret metal complex mixed with a dispersing, i.e., deflocculating or suspending agent, and, if desired, a finely divided solid carrier and/or a wetting agent. The dithiobiuret metal complex can be in particulate form or absorbed on the carrier and preferably constitute at least about more preferably at least about 25%, by weight of the composition. The concentration of the dispersing agent should in general be between about 0.5 and about 5% by weight of the total composition, although larger or smaller amounts can be used if ,desired.

The dispersing agent used in the composition of this invention can be any substance having definite dispersing, i.e., deflocculating or suspending properties, as distinct from wetting properties, although these substances can also possess wetting properties as well.

The dispersant or dispersing agent used can be protective colloids such as gelatin, glue, casein, gums, or a synthetic polymeric material such as polyvinyl alcohol and methyl cellulose. Preferably, however, the dispersants or dispersing agents used are sodium orcalcium salts of high molecular weight sulfonic acids, as for example, the sodium or calcium salts of lignin sulfonic acids derived from sulfite cellulose waste liquors. The calcium or sodium salts of condensed aryl sulfonic acid, for example, the products known as Tamol 731 are also suitable.

The wetting agents used can be nonionic type surfactants, as for example, the condensation products of fatty acids containing at least 12, preferably 16 to 20, carbon atoms in the molecule, or abietic acid or naphthenic acid obtained in the refining of petroleum lubrieating oil fractions with alkylene oxides such as ethylene oxide or propylene oxide, or with both ethylene oxide and propylene oxide, as for example, the condensation product of oleic acid and ethylene oxide containing about 6 to ethylene oxide units in the molecule. Other nonionic wetting agents like polyalkylene oxide polymers, commercially known as Pluronics" can be used. Partial esters of the above acids with polyhydric alcohols such as glycerol, polyglycerol, sorbitol, or mannitol can also be used.

Suitable anionic wetting agents include the alkali metal salts, preferably sodium salts, of sulfuric acid esters or sulfonic acids containing at least 10 carbon atoms in a molecule, for example, the sodium secondary alkyl sulfates, dialkyl sodium sulfosuccinate available under the registered trademark T eepol, sodium salts of sulfonated castor oil, sodium dodecyl benzene sulfonate.

The final wettable powder should preferably have an average particle size of 510,u..

Where the toxicant itself is a liquid these materials can be sprayed on crops or fungi without further dilution.

Petroleum hydrocarbon fractions used as solvents should preferably have a fiash point above 73 R, an example of this being refined aromatic extract of itemsene. Auxiliary solvents such as alcohols, ketones, and polyalkylene glycol ethers and esters can be used in conjunction with these petroleum solvents. p

The treatment rates range from'.l to 3 lbs/acre of the active ingredient with a preferred range of .1 'to lb./acre. The materials are applied at optimum timing so as to have the desired effect on the particular crop. Therefore, applications may be made once or more than once depending on plant species or varieties, cultural conditions, environmental conditions for the particular type of effect desired. -In addition to defining activity as growth regulants, the subject metal complexes also possess fungicidal .activity. In order to demonstrate the effectiveness of these compounds as growth regulants and as fungicides, the

following examples are hereinafter presented. 7

EXAMPLE 1 .ingredients with varying amounts of acetone as an auxiliary solvent, adding thereto 100 parts'per million by weight of a commercial wetting agent consisting of Triton X 100 and diluting this premixture with water to the desired concentration indicated in the table hereinbelow. Triton X 100 is one of a line of commercial surfactants produced by Rohm and Haas Company and is a liquid alkyl aryl polyether alcohol that is an acid stable detergent and is-nonionic in character as an emulsifier. It is prepared by reaction of an alkylphenol with ethylene oxide.

The spray solution containing the active fungicide was applied as a protectant spray to tomato plants. After the deposit had dried, Phytophthora infestans spores were ap plied. Disease ratings were taken in 7-10 days. The results are shown in Table I.

TABLE L-FUNGICIDAL ACTIVITY Late blight activity of metal complexes Percent control ferric chloride adduct of 1,l,5,5-totmmethyl 3- 1,1,5,5-tetmmethyl 3- Percent control zinc chloride adduct of Bates, p.p.m'. (scetone' dimethylsminodlthlodlmethylemlnodlthlowater solution) bluret httn'et 100 100 100 90 so 60 7o 40 50 EXAMPLE 2 Days to cotton 7 day growth petiole abregulant effect scisslon on bean seedlings Treatment-Lunch]: only control 6 No effect. Ferric chloride adduct of 1,1 5,5-tetra- 2 New growth abmethyl 3 ilmethylnminodithiobluret. scissed.

Compound In the stability test procedure the dithiobiuret ingredient is deposited on a piezoelectric quartz crystal which functions as a sensitive microbalance. When electrically excited, the high frequency vibrations of the quartz plates are inversely proportional to the mass of the material present on the plate, whereby the change in frequency is calibrated as a rate of loss in weight due to decomposition of the dithiobiuret ingredient. Then change in weight is 'Zlnc chloride adduct 01 1,1,5,5rtetramethyl-3- 7 t noted gt'am's'per minute per cm? as a function of "the exposure to an ultravi'olet'light source when compared with the visible light containing no ultraviolet ingredient.

:The results of the stability testare given in Example 3.

In order to compare the U.V. stability of'the starting 'dithiobiurets with the metal complexed dithiobiurets the following evaluation was conducted:

. ExAM'i L 3 EFFECT OF METAL COMPLEXING 'or' DITHIOBIURETS ON MAINTAINING THEIR STABILITX AGAINST U .V. EXPOSURE I voiaan me at 8 F gmsJrninrcm Visible I a "light UN. Sample '1 f manly exposure l,l,5g-tetramethyl-3'dimethylami nodithloblu- Nzl 7.6)(10' re =Ferric chlortdeadduct 0t l,l,5,5-tetmmethyl 3- Nzl N :1 dimethylamlnodithlobiuret.

Nil N:1

dimethylamlnodithlobiuret This example definitely shows thatrnetal of the dithiobiurets does provide the resulting Complex with stability. towards U.V.. degradation to the, parent compounddemonstrates instability.

.In. Summary, the, unique propertiesof these compounds :are useful as abscission-control agents'to; adjust the rate and timing of abscission of fio'wers, fruits, (including citrus stone, pome fruits), nuts, berries, floral and. vegetable crops; as mature crop harvest aids applied-i to.1a te i; stages of the maturing crop to control the rate of final development and maturation of the crop and regulate the timed abscission of the mature fruit, vegetables, nuts or berries;

"expression modifiers applied to cucurbits to increase the ratio of female to male flowers thereby increasing subsequent crop yields; as a preventative of sucker shoots from growing on'tobacco plants thereby stepping up the prime leaf yield so as to reduce the growers costs; as a preventative of wrinkling and shrinking or softening of fresh vegetables when stored or shipped; as a preventative jof the sprouting of onions and potatoes when in storage.

The plant growth regulants mentioned hereinabove, al-

though safe to handle, and operative under very favorable conditions over a longer period of application time, nevertheless'mus't be employed within a relatively narrow limit 'of concentration or else overthinning, epinasty, and other serious'damage to foliage and shoots will occur.

What is claimed is:

1. A compound of the formula wherein each of R R R R R and R is C C alkyl; M is a metal selected from the group consisting of zinc, copper and manganese; X is an anion selected from the group consisting of chloride, bromide, iodide, sulfate,

nitrate, phosphate and acetate; and n isan integer determined by thevalence of the metal atom.

2. A compound according to claim 1 which is the zinc chloride adduct of 1,1,5,5 tetramethyl 3 dimethylaminodithiobiuret.

References Cited FOREIGN PATENTS 7/1952 France.

OTHER REFERENCES Usatenko et al., Chemical Abstracts, 1964, columns 12041-2.

DANIEL E. WYMAN, Primary Examiner A. P. DEMERS, Assistant Examiner US. Cl. X.R. 260-429.9, 438.1 

